Picture data compressing and recording apparatus for recording components of the picture independently

Abstract

A picture data compressing and recording apparatus divides picture data into blocks and applies two-dimensional orthogonal transformation to the blocks of picture data. The apparatus records DC components and AC components of the transformed data collectively yet, independently of each other in a recording medium. The apparatus is capable of reproducing a simplified picture by reading out the DC component only. The apparatus is also capable of recording a luminance signal Y and chrominance signals Cr and Cb independently of each other and reading out the luminance signal Y only so as to reproduce a black-and-white picture.

What is claimed is: 
     
       1. A data compressing and recording apparatus for dividing digital picture data which constitute a single picture into a plurality of blocks, applying a two-dimensional orthogonal transform coding to the picture data of individual blocks, and recording the coded picture data in a recording medium, said apparatus comprising: orthogonal transforming means for applying a two-dimensional orthogonal transformation to a plurality of blocks of digital picture data;   said orthogonal transforming means individually transforming DC components and AC components of said digital picture data to produce transformed DC component data and transformed AC component data;   normalizing means for normalizing at least said transformed AC component data of the data transformed by said orthogonal transforming means;   coding means for coding, from among the data transformed by said orthogonal transforming means and the data normalized by said normalizing means, at least the normalized data; and   control means for controlling said normalizing means and said coding means;   said control means controlling an order of normalizing and coding of said transformed DC component data and said transformed AC component data of said digital picture data;   said control means controlling a recording of the DC component data and the AC component data in the recording medium such that the DC component data is recorded prior to the AC component data.   
     
     
       2. A data compressing and recording apparatus for dividing digital picture data which constitute a single picture into a plurality of blocks, applying a two-dimensional orthogonal transform coding to the picture data of individual blocks, and recording the coded picture data in a recording medium, said apparatus comprising: orthogonal transforming means for applying a two-dimensional orthogonal transformation to a plurality of blocks of digital picture data;   said orthogonal transforming means individually transforming DC components and AC components of said digital picture data to produce transformed DC component data and transformed AC component data;   normalizing means for normalizing at least said transformed AC component data of the data transformed by said orthogonal transforming means;   coding means for coding, from among the data transformed by said orthogonal transforming means and the data normalized by said normalizing means, at least the normalized data; and   control means for controlling said normalizing means and said coding means so that said transformed DC component data are normalized and coded before said transformed AC component data are normalized and coded;   said control means causing the coded DC component data to be recorded in the recording medium before the coded AC component data are recorded in the recording medium;   said control means controlling a recording of each of the coded DC component data and the coded AC component data in the recording medium in a specific order of luminance signal data then chrominance signal data.   
     
     
       3. A data compressing and recording apparatus for dividing digital picture data which constitute a single picture into a plurality of blocks, applying two-dimensional orthogonal transform coding to the picture data of the individual blocks, and recording the coded picture data in a recording medium, said apparatus comprising: orthogonal transforming means for applying a two-dimensional orthogonal transformation to a plurality of blocks of digital picture data;   said orthogonal transforming means individually transforming DC components and AC components of said digital picture data to produce transformed DC component data and transformed AC component data;   normalizing means for normalizing at least said transformed AC component data of the data transformed by said orthogonal transforming means;   coding means for coding, from among the data transformed by said orthogonal transforming means and the data normalized by said normalizing means, at least the normalized data; and   control means for controlling said normalizing means and said coding means so that said transformed DC component data are normalized and coded before said transformed AC component data are normalized and coded;   said control means causing the coded DC component data to be recorded in the recording medium before the coded AC component data are recorded in the recording medium;   said control means controlling a recording of each of the coded DC component data and the coded AC component data in the recording medium in a specific order of chrominance signal data, then luminance signal data.   
     
     
       4. The apparatus as claimed in claim 1, wherein individual component data are recorded on a picture basis in picture data areas within the recording medium and addresses of said individual component data are recorded in a directory area within the recording medium, said directory area being a separate physical area from said picture data areas. 
     
     
       5. The apparatus as claimed in claim 1, wherein said recording medium comprises a plurality of recording areas for storing the picture data, each recording area being divided into a plurality of recording units, each recording unit having a predetermined recording capacity, said picture data being recorded in said plurality of recording areas while being supervised on a recording unit level; and said recording medium further comprising an area for recording a memory allocation table, said memory allocation table indicating a relationship among the plurality of recording areas in which a group of associated data is recorded.   
     
     
       6. The apparatus as claimed in claim 4, wherein said recording medium comprises a plurality of recording areas for storing the picture data, each recording area being divided into a plurality of recording units, each recording unit having a predetermined recording capacity, said picture data being recorded in said plurality of recording areas while being supervised on a recording unit level; said recording medium further comprising an area for recording a memory allocation table, said memory allocation table indicating a relationship among the plurality of recording areas in which a group of associated data is recorded; and   said directory area indicating the recording area in which a leading portion of a group of associated data is recorded.   
     
     
       7. The apparatus as claimed in claim 6, wherein either said area for said memory allocation table or said directory area of the recording medium indicates whether or not to inhibit write-in and erasure of the recording area with which said area for said memory allocation table or said directory area is associated. 
     
     
       8. A method for compressing digital picture data and recording the compressed digital picture data in a recording medium, comprising the steps of: (a) dividing the digital picture data of a single picture into a plurality of blocks;   (b) applying a two-dimensional orthogonal transform coding to the digital picture data of individual blocks, the transformation being performed individually on D.C. components and AC components of the digital picture data, thereby generating transformed DC component data and transformed AC component data;   (c) normalizing at least the transformed AC component data of the data transformed in said step (b);   (d) coding, from among the data transformed in said step (b) and the data normalized in said step (c), at least the normalized data; and   (e) recording the DC component data in the recording medium prior to recording the AC component data in the recording medium.   
     
     
       9. The method as claimed in claim 8, wherein said step (e) further comprises the step of: (f) recording each of the DC component data and the AC component data in the recording medium in a specific order of luminance signal data, then chrominance signal data.   
     
     
       10. The method as claimed in claim 8, wherein said step (e) further comprises the step of: (f) recording each of the DC component data and the AC component data in the recording medium in a specific order of chrominance signal data and luminance signal data.   
     
     
       11. The method as claimed in claim 8, wherein said step (e) further comprises the steps of: (f) recording individual component data on a picture basis in picture data areas of the recording medium; and   (g) recording addresses of the individual component data in a directory area of the recording medium.   
     
     
       12. A data compressing and recording apparatus for dividing digital picture data which constitute a single picture into a plurality of blocks, applying a two-dimensional orthogonal transform coding to the picture data of individual blocks, and recording the coded picture data in a recording medium, said apparatus comprising: orthogonal transforming means for applying a two-dimensional orthogonal transformation to a plurality of blocks of digital picture data;   said orthogonal transforming means individually transforming DC components and AC components of said digital picture data to produce transformed DC component data and transformed AC component data;   normalizing means for normalizing at least said transformed AC component data of the data transformed by said orthogonal transforming means;   coding means for coding, from among the data transformed by said orthogonal transforming means and the data normalized by said normalizing means, at least the normalized data; and   control means for controlling said normalizing means and said coding means;   said control means controlling an order of normalizing and coding of said transformed DC component data and said transformed AC component data of said digital picture data;   said control means controlling a recording of the DC component data and the AC component data in the recording medium such that the DC component data is recorded in the recording medium in a frame separate from the AC component data being recorded in the recording medium, thereby recording the DC component data at a frame having no AC component data recorded therein.   
     
     
       13. The data compressing and recording apparatus as claimed in claim 12, wherein said control means controls a recording of the DC component data and the AC component data in the recording medium such that the DC component data is recorded prior to the AC component data.